a = [198, 232, 816, 200, 1536, 300, 6144, 984, 51200, 570, 92160, 1200, 565248, 756, 1474560, 800, 6291456, 1782, 65536000]
flag = ''
for i in range(len(a)):
    if (i+1)&1:
        flag += chr(a[i]>>(i+1))
    else:
        flag += chr(a[i]//(i+1))
print(flag) # ctf2020{d9-dE6-20c}